Flexbox: Reorder And Stack Columns

I have three columns, which I want to swap the order of at a certain screen size. The current order is two 1/4 width columns with a 1/2 width in between. I want to make the two 1/

Solution 1:

The key to this layout is switching the flex container to column wrap in the media query.

You also have to define a height for the container, so the items know where to wrap.

.col-container {
  display: flex;
}
.col1of2 {
  width: 50%;
  background: red;
}
.col1of4 {
  width: 25%;
  background: yellow;
}
.col1of4--last {
  background: blue;
}
@media all and (max-width: 1000px) {
  .col-container {
    flex-direction: column;
    flex-wrap: wrap;
    height: 100px;
  }
  .col1of2 {
    order: 1;
  }
  .col1of4 {
    width: 50%;
  }
}

<div class="col-container">
  <div class="col col1of4">
    <div class="col__inner">sssadksadkaslkslasasldkasddsa</div>
    <div class="col__inner">sssadksadkaslkslasasldkasddsa</div>
  </div>
  <div class="col col1of2">
    <div class="col__inner">sssadksadkaslkslasasldkasddsa</div>
    <div class="col__inner">sssadksadkaslkslasasldkasddsa</div>
    <div class="col__inner">sssadksadkaslkslasasldkasddsa</div>
    <div class="col__inner">sssadksadkaslkslasasldkasddsa</div>
  </div>
  <div class="col col1of4 col1of4--last">
    <div class="col__inner">sssadksadkaslkslasasldkasddsa</div>
    <div class="col__inner">sssadksadkaslkslasasldkasddsa</div>
  </div>
</div>

revised fiddle